Sep 05 (NHK) - Large numbers of pearl oysters have been found dead in Ago Bay in central Japan.
The bay is located in the city of Shima in Mie Prefecture. The region is known as the birthplace of pearl cultivation and a major production center in Japan.
The Mie Prefecture Fisheries Research Institute says dead Akoya pearl oysters with shrunken mantles were discovered in July. It also says it was later confirmed that oysters in a neighboring town had the same damage to the lining of their shells.
The institute says more than 80 percent of the respondents among the 300 pearl cultivation businesses it surveyed reported oyster deaths.
The cause of the deaths has not yet been determined. The institute has asked the central government and others to investigate.
Die-offs of young Akoya oysters have also been confirmed in the western prefecture of Ehime. Both young and adult oysters have died in Mie. An industry group there says pearl shipments from Mie are expected to decline.
Isao Kuriyama of the institute says the die-offs are unprecedented and it will likely take time to determine the cause. He added that officials will consult with related firms to devise a course of action.
